The present invention relates generally to ignition coils for an internal combustion engine. More specifically, the invention relates to a terminal for an ignition coil, and the connection between the terminal and the ignition coil housing.
Ignition coils typically contain a core assembly constructed of steel lamination stacks upon which primary and secondary windings of the assembly are mounted. The primary and secondary windings are typically comprised of copper wire and are typically each wound around a respective bobbin. The core assembly, the primary and secondary windings, and their respective bobbins are all disposed within an ignition coil housing. A terminal is typically coupled with the housing, as will be discussed in further detail below, in order to form an electrical connection with the secondary winding. An encapsulate material, such as a thermosetting resin, may be poured into the housing in order to secure the above-described assembly within the housing.
Currently, terminals are secured to ignition coils by various types of connections. In one such connection, the terminal is insert molded into the housing. More specifically, the terminal is inserted into a mold, and the housing is formed around the terminal through various methods such as injection molding. However, insert molding includes complexities such as tooling the mold and properly inserting the terminal into the mold. Additionally, the terminal may interfere with other desired features of the housing, such as various other insert molded components.
In another connection between the terminal and the ignition coil, the terminal is inserted through a bore in the housing and into electrical connection with a metal bracket that is in turn in electrical connection with the secondary winding. However, the terminal and the housing may not effectively form a seal in order to prevent the encapsulate material from leaking through the housing bore and about the terminal.
In yet another connection between the terminal and the ignition coil, the housing includes a collar having an outer surface engaged with an opening in the housing. The collar also includes an inner surface having internal threads for threaded connection with a threaded portion of the terminal. However, this design requires additional manufacturing steps and additional components, such as the threaded insert.
Therefore, it is desirous to provide an ignition coil that prevents encapsulate from leaking out of ignition coil housing and that minimizes manufacturing complexity.